diff --git a/phpBB/styles/prosilver/template/attachment.html b/phpBB/styles/prosilver/template/attachment.html
index 6c1ed01da9..58c82cb7ea 100644
--- a/phpBB/styles/prosilver/template/attachment.html
+++ b/phpBB/styles/prosilver/template/attachment.html
@@ -35,7 +35,7 @@
 			{% if _file.COMMENT %}<dd><em>{{ _file.COMMENT }}</em></dd>{% endif %}
 			<dd>{{ _file.DOWNLOAD_NAME }} ({{ _file.FILESIZE }} {{ _file.SIZE_LANG }}) {{ _file.L_DOWNLOAD_COUNT }}</dd>
 			<dd>
-				<audio controls="controls" preload="none" style="max-width:100%;width:360px">
+				<audio class="file-audio-controls" controls="controls" preload="none">
 					<source src="{{ _file.U_DOWNLOAD_LINK }}" type="{{ _file.MIMETYPE }}">
 				</audio>
 			</dd>
diff --git a/phpBB/styles/prosilver/theme/content.css b/phpBB/styles/prosilver/theme/content.css
index 338016ac2c..1313e6b604 100644
--- a/phpBB/styles/prosilver/theme/content.css
+++ b/phpBB/styles/prosilver/theme/content.css
@@ -682,6 +682,10 @@ dl.thumbnail dt a:hover img {
 	border: 1px solid transparent;
 }
 
+audio.file-audio-controls {
+	max-width: 100%;
+}
+
 /* Post poll styles
 ---------------------------------------- */
 fieldset.polls {